Field of the Invention
The invention relates to a semifinished product of a multi-junction solar cell and a method for producing a solar cell.
Description of the Background Art
U.S. Pat. No. 4,744,194 discloses a method for removing III-V based solar cell layers from a supporting substrate by means of selective chemical etching processes. In addition, methods for separating semiconductor layers from their substrates based on chemical etching processes are known from U.S. Pat. No. 4,883,561 and US 2010/0116784 A1. The separation of semiconductor layers by means of the ion implantation method is known from U.S. Pat. No. 5,374,564. Furthermore, optical methods for separation of semiconductor materials, in particular separation of LED layers based on group III nitrides from substrates with large band gaps, are known from DE 196 49 594 A1, which corresponds to U.S. Pat. No. 6,211,950, and from U.S. Pat. No. 6,071,795. Additionally, another solar cell structure is known from U.S. Pat. No. 7,785,989 B2.